Reading this short piece by Jobst Brandt (courtesy of Sheldon, RIP) was very important in my education regarding square taper cranks, it's worth a look:
http://sheldonbrown.com/brandt/installing-cranks.html Basically: 1. When installing or re-installing cranks, they should be tightened to adequate torque once and then left until they are removed; they will naturally tighten themselves further onto the spindle during riding. As a result, the crank bolts will naturally lose preload (i.e. they will feel "loose" if you go to tighten them again), but they should not be retightened after initial instillation. Doing so will cause overtightening, leading to a distorted taper hole or possibly crank failure. 2. If a crank becomes loosened over time, it is because the taper hole is distorted, and Eric would be right that at this point they are "beyond repair." This most commonly happens on left cranks, and thus you can usually buy replacement left cranks fairly easily (i've gotten replacement left sugino XD crank arms from Jenson USA for like $20- check it out). 3. A small amount of grease is okay on the spindle during instillation; it helps achieve a more predictable press fit for a given torque on the crank bolts (i basically run a greasy finger over the spindle before installing--so not a lot). I've stuck by these rules for a few years and it has done me well. I've replaced left cranks arms for cheap if they get a little creaky, but haven't had cranks wear out to the point of loosening in a while. On Jul 22, 6:09 pm, EricP <ericpl...@aol.com> wrote: > Dunno, maybe my Sam Hillborne has a personality. Or at least a > preference for parts. As in, it's cranky. > > A ride to the grocery store to get some Welsh cheddar cheese and > Vermont smoked bacon after work precipitated the left crank arm coming > loose. As in, wobble and about to fall off. Huh. Now, not only is > that the second time in the past week this has happened, but it is now > the second Sugino crankset and Tange bottom bracket this bike has > rejected. > > Luckily, still had the replacement crankset/bottom bracket combo that > was removed a couple of months ago for this Sugino. After a bit over > a half hour of work, the Shimano Deore with external BB is back on the > bike. Thankfully hadn't thrown the spacers into my parts bin or > anything. > > Now, am not blaming anyone or anything. The crank that just failed > was used. And more than likely there was an error in my installation. > Just sort of funny that with the more traditional build of this bike, > the crank is thoroughly modern. > > Aww, if nothing else, it gave me an excuse to pull out that pun of a > subject line. > > Eric Platt > St. Paul, MN -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bu...@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
